Flavonoids from Selaginella uncinata

In the current study, nine flavonoids were isolated and purified from 75% ethanol extract of Selaginella uncinata (Desv.) Spring by column chromatographic techniques over macroporous resin, polyamide, silica gel, Sephadex LH-20 and pre-HPLC. On the basis of their physico-chemical properties and spectroscopic data analyses, these compounds were elucidated as cirsimarin (1), nepitrin (2), apigenin-6-C-α-L-arabinopyranosyl-8-C-β-D-glucopyranoside (3), apigenin-6-C-β-D-glucopyranosyl-8-C-α-L-arabinopyranoside (4), apigenin-7-O-β-D-glucopyranoside (5), 2,3-dihydroamentoflavone (6), 4'-O-methylamentoflavone (7), 2,3-dihydro-4'-O-methyl-amentoflavone (8), and 2,3,2",3"-tetrahydron-4'-O-methyl-robustaflavone (9). Compounds 1-5 belong to flavonoid glycosides and were isolated from the genus Selaginella for the first time.